Switching systems and apparatus therefor



4, 1959 v R. J. BER ET AL 2,898,452

SWITCHING SYSTEMS AND APPARATUS THEREFOR Original Filed D60. 13, 1954 Sheets-Sheet l SEPARATOR &

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Aug. 4, 959 R. J. BERTI ET AL 2,898,452

SWITCHING SYSTEMS AND APPARATUS THEREFOR Original Filed D80. 13, 1954 15 Sheets-Sheet 2 A B C p l I 259-2 i ML G 2 i k/ 3 sm e i I 4 M m0 E 5 :ws-fi 6 PILOT BALL A B C" RELAY RELAY RELAY RELAY RELAY 9 i l I I w 3 I l IF? 4 WTJ\ 5 1959 R. J. BERT! ET AL 2,398,452

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SWITCHING SYSTEMS AND APPARATUS THEREFOR Original Filed'Dec. 13. 1954 15 Sheets-Sheet 9 1% MA 7 New Aug. 4, 1959 R. J. BERT! ETAL 2,398,452

SWITCHING SYSTEMS AND APPARATUS THEREFOR Original Filed Dec. 13, 1954 15 Sheets-Sheet 1O PDCBA DCBA INVENTORS.

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SWITCHING SYSTEMS AND APPARATUS THEREFOR Original Filed Dec. 15, 1954 15 Sheets-Sheet 12 z Yaw-0 Aug. 4, 1959 R. J. BERTI ET AL 2,898,452

SWITCHING SYSTEMS AND APPARATUS THEREFOR Original Filed Dec. 13, 1954 15 Sheets-Sheet 13 VSl-M64 Z ya/l/aafimw Aug. 4, 1959 R. J. BERT! ET AL 2,898,452

SWITCHING SYSTEMS AND APPARATUS THEREFOR Original Filed D80. 15. 1954 15 Sheets-Sheet 14 Q XI r 1 T ATiS n INVENTORS.

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R. J. BERTI ETAL 2,898,452

SWITCHING SYSTEMS AND APPARATUS THEREFOR l5 Sheets-Sheet 15 Aug. 4, 1959 Original Filed Dec. 15, 1954 INVENTQRS; Tsl r52 United States Patent SWITCHING SYSTEMS AND APPARATUS THEREFOR Roland J. Berti and David C. Bettison, Omaha, Nebr.

Original application December 13, 1954, Serial No. 474,668. Divided and this application October 5, 1955, Serial No. 538,707

'15 Claims. (Cl. 246-134) This application is filed as a division of our copending application entitled Switching Systems and Apparatus Therefor, filed December 13, 1954, Ser. No. 474,668.

This invention relates to switching systems and apparatus therefor and more particularly is concerned with apparatus for automatically controlling the track switches of a railway classification yard or hump yard system.

This invention further contemplates an arrangement for storing control intelligence in the apparatus and for indicating portions of the stored intelligence.

A railway classification yard or hump yard is a storage area wherein railway cars are classified and stored in accordance with their ultimate destinations. 'Ihus, cars destined for point A are stored on a single track, cars destined for point B are stored on a separate single track, and so on. The yard is composed of a single entrance track that passes over a hump or a hill and then branches out through an appropriate number of track switches and branch sections of track into a large number of storage tracks.

In the classification process the cars are successively moved along the single entrance track, permitted to run down the hump by gravity in close succession, and then selectively guided to their respective storage tracks, as determined by their ultimate destination. It has long been recognized that the frequent switching operations required at each of the switch points in the yard layout renders manual methods of control too costly and slow, and accordingly several types of automatic control apparatus have been developed and employed.

One such prior art system is shown in the Brixner et al. Patent No. 2,194,352 which discloses an automatic storage and control system employing a plurality of individual train describer units at each of the major switch points of the yard layout. Each train describer unit comprises a plurality of storage relays that are adapted to assume individual patterns of energization and de-energization for each track destination desired. Each train describer unit is able to store a single destination, and thus the number of units required is determined by the number of car destinations to be stored. The various describer units at each switch point are connected in step-by-step relationship so that control intelligence may be stored at each switch point and advanced through the relay system as the preceding unit of intelligence becomes operative and passes to the next point of the system.

As the car progresses along the route to its storage track, the operative train describer unit throws its associated track switch in the prescribed direction as determined by the condition of energization of its storage relays, and repeater contacts on relays associated with each such switch then close circuits for transmitting the stored information in that train describer unit to the train describer units associated with the succeeding switch point in theroute selected.

The present invention ofiers numerous operating advantages over these prior art arrangements and the present 2,898,452 Patented Aug. 4, 1959 improvements are believed important and necessary in any complex classification apparatus.

When a train is to be classified, it is desirable to be able to record the destination for each of the cars in a single operation, and due to the length of modern freight trains, this often requires the storage of more than a hundred car destinations. In all known commercial embodiments involving storage relays, the memory system portion of the apparatus is able to store only five car destinations with the result that the humpmaster must continually refer to the master sheet for the train being classified and set up successive increments of the train as the system proceeds to use up the destinations then in the machine. It is, of course, possible to make provision for storing more than five destinations but the cost and size of the device becomes prohibitive.

During the classification process, it frequently is necessary to reroute a car after its original route has been recorded in the automatic storage and control apparatus. This may occur either due to an error in originally classifying it or more frequently because it is found to be in need of repair. Usually one of the storage tracks is a repair track and all cars needing repairs are routed to this'track regardless of their ultimate destination. In most hump yards, an inspection pit is situated immediately before the hump so that cars in need of repair may be discovered and rerouted before passing over the hump.

In these instances it is necessary to cancel the routing originally recorded in the control apparatus for the car 7 in question and substitute a new routing. Variations of this problem may also arise in that a particular car may be omitted when setting up the original routings with the result that its routing must later be inserted or a car destination may inadvertently be recorded twice and, hence, one such recording must later be cancelled. In the prior art devices employing storage relays in the memory system, it has not been possible to selectively cancel out or substitute at an intermediate point but, rather, all subsequently recorded destinations must first be cancelled and, after the necessary corrective action, must then be reinserted.

The present invention seeks to overcome the above limitations of the prior art devices and has for its principal object the provision, in control apparatus for automatic switching systems, of one or more of the following features or attributes: Means for representing the control intelligence by selected permutations of mechanical elements each of which has one of two distinctive physical characteristics; means for forming the desired code groups; means for verifying that the code group selected corresponds to the destination desired, including means for dumping any erroneous code groups; means for storing a plurality of code groups to permit a plurality of car destinations to be recorded simultaneously; means for indicating the destinations represented by certain of the stored code groups; means for individually cancelling and/or substituting one or more code groups in the storage section; and means comprising a series of control levels that may be correlated with the switch levels of the track layout, whereby the code groups progress through the control apparatus in timed relation with the progress of the cars through the classification yard.

In accordance with the invention, it is proposed to employ gravity actuated, free rolling elements each having one of two distinctive physical characteristics and it is proposed to arrange these elements within a plurality of tubes, whereby a plurality of code groups may be maintained in their correct permutational arrangement within the storage devices. It is further proposed to permit the code groups within the indicating portion of the storage apparatusto be cancelled and/or substituted as'desired.

In addition, the present invention contemplates the use to the maximum extent possible of existing signalling and switching equipment of classification yards such as the track circuits and switch machine control circuitry and is particularly adapted for use in conjunction with automatic control systems for car retarders.

It is further proposed to provide a mechanical control system in lieu of electrical storage relays and thereby ofier the advantages of increased operating flexibility and lower cost. The mechanical system is capable of use with any size classification yard and many of the basic components are. of identical construction permitting necessary. expansion at a minimum of cost.

. The invention contemplates the provision of a large storage capacity to permit the humpmaster to record and store the classification routes for an entire train during a single operation and thus devote his undivided attention to supervising the actual classification operation. Furthermore, the system may be provided with a large storage capacity merely by increasing the size of the storage containers for the mechanical elements whereas in the electrical relay systems an additional bank of relays is required for each additional unit of storage.

7 Other objects and advantages of the invention will be apparent during the course of the following description.

' In'the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Fig. 1 is a block diagram representing the arrangement of'thegeneral system of the present invention;

Fig. '2 is a one-line diagram of the track layout of atypical classification yard;

Fig. 3 is a relay tree circuit corresponding to the track layout of Fig. 2 p

Fig. 4 is a code chart illustrating the combinations and permutations of code elements necessary to describe the various classification routes in the track layout of Fig. 2;

Figs. 5. and 6 are schematic front sectional and side elevational views of the general arrangement of the preferred form of the present invention;

Fig. 7 is a view of the console control box employed by the operator to control the various classification operations;

Fig. 8 is a perspective view of a selector shuttle;

Fig. 9 is a sectional view of the magnetic separator taken in a horizontal plane, as indicated by the line 9 -9 of Fig.

Fig. 10 isa side view partly in section of a coderouting station of the present invention;

Fig. 11 is a perspective view of a code-handling cylinder;

Fig. 12 is a sectional view of the code-routing station taken in a vertical plane, as indicated by the line 12-12 of Fig. 10;

Fig. 13 is a perspective view of one of the guide chambers of the code-routing station;

Fig. 14 is a perspective view of one of the exit tubes of the code-routing station;

Fig. 15 is a perspective view of a mounting shield for the sensing coils of the present invention;

Figs. 16 and 17 are fragmentary vertical sectional views, as viewed from the rear, of the code station of the verifier section illustrating the operation of the mechanical fingers;

Fig. 18 is a side view partly in section of a code transfer station of the present invention;

'a a sa r Fig. 22 is a circuit diagram of the push button selector arrangement and reservoir motor control;

Fig. 23 is a circuit diagram of the solenoid selector arrangement;

Fig. 24 is a circuit diagram of the detector portion of the verifier circuitry;

Fig. 25 is a relay tree circuit controlled by the circuit of Fig. 24;

Fig, 26 is a diagram of the verifier cylinders control circuitry;

Figs. 27A and B illustrate the cascading control cir c uit ry of the visible storage section;

Fig. 28 is a diagram of the reminder circuitry associated with the blind storage section;

Figs. 29 and 30 are diagrams of the full code warning circuitry associated with the blind storage section; and

Figs. 31 and 32 are diagrams of the track switch control circuitry.

General system The present invention recognizes that each storage track in a railroad classification yard can be described in terms of the switch points through which a car must pass in reaching that track. At each switch point the track switch may assume one of two positions, and therefore each switch point in the classification route of any given car may be represented by an element having one of two diiferent physical characteristics. For instance, if the switch is to be thrown to the right, then an element having a certain characteristic is employed, whereas if the switch is to be thrown to the left, then an element having a different characteristic is employed.

In order to, describe a particualr storage track, it is necessary to provide a permutational group of elements equal in number to the number of switch points traversed by the car and differing in physical characteristics according to the position which each track switch must assume. In the present invention it has been found most advantageous to employ mechanical elements for this purpose and more particularly to employ flowable me-. chanical elements such as balls. In the preferred form, metallic balls and non-metallic balls provide the necessary distinguishing characteristics, but this specific disclosure is not intended to limit the broad scope of the general system of the present invention.

Referring to Fig. l, which is a block diagram illustrating the general system, there is graphically depicted the sequence of operations that the mechanical elements of the track switch control apparatus must undergo. The mechanical elements are initially deposited in the left and right hand compartments 4tland 41, respectively, of a reservoir 42, elements of one characteristic being placed in compartment 46 and elements of a different characteristic in compartment 41.

Fromthe reservoir 42, the elementsare fed into a code assembly section 43 wherein the proper number of elements of appropriate characteristic are selected and arranged in permutational groups to define the routing pattern for thecars t o beclassified. A code assembly operator 45 is associated with the code assembly sec: tion and is adapted to control the selection of the code groups. The operator may be actuated either manually or automatically and may be situated adjacent the remainder of the apparatus or at a remote point as de: termined by the requirements of the particular appli: cation. After assembly, the code groups are passed into a verifier 46 wherein provision is made for checking or verifying the correctness of the assembled code groups and this is displayed by a verifier indicator 47. If the verifier 46 finds that the assembled code group correetly corresponds to the destination selected, then the group of code elementsis passed into the next or blind storage section of, the apparatus whereas. if the assembled code group is found to be incorrect, it is automatically removed from the apparatus and the selection procedure is repeated.

The blind storage section 49 consists of the containers necessary to house and store in their propertly selected order the many mechanical elements required to record the classification routing paths of the individual cars of modern freight trains. It has been found that a mechanical storage system permits a large number of train destinations to be stored with little additional expense and theoretically has no maximum limit of storage capacity.

The code elements progress through the blind storage section and emerge at the visible storage section 50 which has associated therewith a visible storage indicator 51 that displays the destinations represented by the code groups contained in the visible storage section. The visible storage section serves as an additional check point for the humpmaster and also furnishes important up-todate information of the transient status of the classification process. The code groups in the visible storage section correspond to the cars that are immediately approaching the hump and are about to be classified. Such information is important to the humpmaster in supervising the operations of the classification yard. For instance, as has been pointed out hereinbefore, it is frequently necessary to reroute certain of the cars and this is preferably handled as they immediately approach the hump. In addition, it may appear that a plurality of successive cars will follow substantially the same route and due to their different speeds will require retarders to maintain them in spaced relationship. It is helpful to be forewarned so that the retarding operations can be coordinated with the classification operations.

There is illustrated in Fig. l a cancelling and substituting section 52 that bypasses the blind storage section 49 and is arranged to facilitate the rerouting of the cars. This section cooperates with the visible storage section 50 in that the visible storage section indicates the necessity of rerouting certain cars and the cancelling and substituting section permits the necessary changes to be carried out. The functions assigned to this section may be divided into three broad categories; namely, (1) cancelling and substituting, (2) cancelling only, and (3) adding a code only. Some of the numerous situations which may give rise to these operations will be discussed more fully hereinafter.

The apparatus of the present invention is coordinated with the classification yard such that a code group passes from the visible storage section 50 to the control section 54 in timed relation with the approach of the car represented thereby to the first or main track switch in the classification yard. The control section may be divided into a series of successive stages that cooperate with the successive levels of the track switches in the physical layout of the yard.

The coordinated advance of the code group from the visible storage section to the control section and subsequently through the various stages of the control section is controlled by a cascade control section 55. At the various stages of the control section 54, the code groups exert their control function to actuate controlled apparatus, as indicated at 56. In the case of a classifica-- tion yard, the cascade control section 55 comprises a plurality of track detector circuits that respond to the presence of a car on the track section with which they are associated and the controlled apparatus 56 comprises a plurality of track switches.

The first level of track switches consists of the first or main track switch; the second level consists of the immediately successive switch in each of the two alternate routes that lead from the main switch; the third level consists of the immediately successive switch in each of the four alternate routes that lead from the second level of switches; and so on, the number of levels being dependent upon the number of ultimate storage tracks. Thus the first, second, and third stages of the control section 54 cooperate with the first, second, and third levels, respectively, of the controlled apparatus 56.

As a car crosses an approach section for the first track switch, the corresponding code group occupies the first stage of the control section, and, assuming that the previous car has cleared the track detector circuit associated with the first track switch, becomes operative to cause the first switch to be thrown in the prescribed direction. This code group is retained in the first stage until the car actuates the track detector circuit for the first track switch, at which time the code group advances to the second stage of the apparatus. The said track detector circuit maintains the positioning of the track switch until the car clears the switch, at which time subsequent code groups may control the positioning of the first switch. Assuming that the preceding cars have now cleared the track detector circuit associated with the second stage of the apparatus, the code group will immediately throw the proper track switch in the prescribed direction, and this step-by-step process continues until the car reaches its ultimate storage track.

After the code elements have exerted their controlling function, they are subsequently deposited in a hopper or collector 58 that guides them to a return conveyor 59. The return conveyor transports the code elements from the hopper to the reservoir 42. Prior to being deposited in the reservoir, the elements are subjected to the action of a separator 69 which separates them in accordance with their different physical characteristics.

It may be seen that the general system of the present invention is independent of the specific form of elements employed though the preferred form is believed to have many operating advantages over other workable forms.

In the preferred form the code elements are freely rolling balls adapted to progress through the system under the force of gravity. Balls of one characteristic are steel, and of the other are glass, and they are distinguished by reason of their different physical characteristics.

It should be understood that other shapes such as cylinders, cubes, oblongs, discs, and the like, may be employed as the mechanical elements and they may be progressed through the system by forces other than gravity such as hydraulic, pneumatic, or magnetic forces. In addition, they may be distinguished from each other by reason of size, weight, conductivity, transparency, or any other suitable criterion, and all of these forms are within the scope of the general system contemplated by the present invention.

General organization of the preferred form Referring now to Fig. 2, there is illustrated a typical classification yard having eight receiving tracks branching out from a single entrance track. Classification yards of this type are analogous to the familiar relay tree circuit patterns and as indicated in Fig. 3 may be represented by such a circuit.

In a yard where each track can always be subdivided into two branch tracks, the number of tracks available with n switching levels is 2 Thus the layout of Fig. 2, which contains four switching levels, theoretically might accommodate sixteen receiving tracks; however, practical considerations of track curvature do not always allow for the successive branching of a particular switching lead. In fact, as shown in Fig. 2, some tracks run directly to the main body of the classification yard from as early as the second switching level.

The receiving tracks, reading from left to right, are designated by reference characters 1 to 8, the directions left and right being determined by standing at the hump or entrance track and facing the receiving tracks. Each of the track switches is labeled SW followed by a pair of numbers designating the receiving tracks spanned by the particular switch. Thus the main switch SWl-S spans all eight receiving tracks whereas switch SW5-8 spans only receiving tracks 5, 6, 7, and 8. It may be seen that the track layout may be divided into a series of levels as follows; The first or A level comprising switch SW1-8; the second or B level, comprising switches SW14 and SWS-S; the third or C level comprising switches SW1-3 and SW6-8; and the fourth or D level comprising switches SW1-2 and SW7-8. Thus it may be seen that any desired path may be described by combining four code elements.

In the preferred form, metallic and non-metallic balls are employed as the code elements, steel balls providing one characteristic and glass balls providing the other, and the arrangement is such that a steel ball will cause a track switch to be thrown to the left whereas a glass ball will cause the switch to be thrown to the right. Accordingly, a code system is shown in Fig. 4 which illustrates the various combinations and permutations of steel and glass balls necessary to describe any desired path, the steel balls being represented by a square with an X and the glass balls being represented by a blank square. Thus a car to be routed to storage track 2 must pass to the left over switches SW1-8, SW1-4, and SW1-3 (three steel balls), and to the right over SW1-2 (glass ball). Where the number of switches to be traversed is less than the maximum number, the excess code element locations are occupied by glass balls which merely function as spacers.

In the preferredv form of the present invention, each code group of balls also includes a steel pilot ball. Its principal functions are to announce the presence of the associated code, group at various locations in the apparatus and to assist in coordinating the advance of the code group through the apparatus in timed relationship with the progress, of the car in the track layout. This will be more fully described hereinafter.

Figs. 5 and 6 are schematic front sectional and side elevational views, respectively, of the preferred form of the invention. In this form successive stages occupy successively lower elevations and the code balls advance through the apparatus under the force of gravity. A power driven return conveyor 102 acts against the force of gravity and elevates the balls from the bottom of the apparatus to the top and the cycle is repeated.

It should, be noted, that in the preferred form the apparatus is divided into five vertical channels corresponding respectively to the pilot channel, and the fourth, third, second, and, first switch levels designated channels D, 0,, B, and A. Many of the parts in the various channels are identical and for convenient reference the parts of the pilot channel are designated by pure numbers and the corresponding parts in channels A, B, C, and D are designated by identical numbers with a suffix letter corresponding to the, particular channel.

The code elements, as delivered by the return conveyor system 102 to a return hopper 104, consist of a mixture Qfi Steel and glass balls. A motor driven worm screw 105 located in the bottom of the return hopper feeds the hallsin single file to a permanent magnet type magnetic separator, generally indicated at 107.

The separator, as best seen in the sectional view of Fig. 9,, includes a frame having a pair of spaced wooden side panels 108 adaptedto support two arcuate strips of silicon steel 109 therebetween. The coplanar silicon steel strips are separated by an air gap having a length of; approximately one-half the diameter of the code balls and are magnetized by small permanent horseshoe magnets 110.

When a steel ball is, fed to the magnetic separator, it followsthe contour of the arcuate strips 1439, ultimately dropping into a steel ball reservoir 111. When a glass halliisfed to the magnetic separator, it follows a tangent pattern into a glass ball reservoir 112. Each reservoir provided with a motor driven worm screw conveyor 114 which progresses the balls past a series ,of short tubes L15, spaced as shownin, Fig. 6., The screw conveyors assure a constant flow of balls to the selector mechanism. Referring to Fig. '5, which is a sectional elevational view of channel D, it may be seen that the tubes D are adapted to feed into individual V-shaped funnels 117D, but the flow of the balls is controlled by the shuttle bars 118D and 119D. A shuttle bar is shown in Fig. 8 and is formed with an aperture 120 adapted to receive one of the code balls. When the shuttle bar is in normal position, the aperture 120 is in register with the bottom end of one of the tubes 115 A ball will drop into the aperture pocket and be supported therein by the horizontal ledges of the funnel 117. As the shuttle bar moves laterally, the aperture will clear the funnel ledges and the ball will pass through the aperture and into the funnel.

The pilot channel, which is always supplied with a steel ball, requires only one shuttle, but each ofthe code channels is provided with a pair of shuttles. The pairs of shuttle bars are selectively operable so. that only one ball is deposited in each funnel at any given instant. With the above exception, all the channels are of identical construction in the reservoir and selector portion of the apparatus.

p The shuttle bars are preferably actuated by solenoids, as indicated at 122D and 123D, and the. necessary control circuitry is shown in Figs. 22 and 23. The operation of these circuits will be described hereinafter. For. the present it suffices to say that when a car is to be routed to a given storage track, an appropriate button corresponding to that track is actuated and the proper code group is deposited in the'V-shaped funnels 117 by the solenoid actuated shuttle bars.

For instance, if it is desired to select a code group representative of receiving track 2, an appropriate button is actuated so that shuttle bars 118, 118A, 118B, 118C, and 119D will operate to deposit a steel ball in each of funnels 117, 117A, 117B, and 117C and a glass ball in funnel 117D.

The funnels 117 each have a hollow depending stem 125 that feeds into a verifier code station 126. The code station 126 includes a code-routing or switching means in the form of a rotatablercylinder 127 that is provided with five axially spaced pockets 128. The cylinder 127 is common to each of the channels and is shown in its normal position with the pockets facing downwardly. With the cylinder so positioned, the group of code balls will remain in the depending stems 125, being in contact with an imperforate surface portion of the cylinder 127.

Each of the stems 125 is provided with a sensing coil 130 adapted to detect the presence of a steel ball. but unresponsive to the presence of a glass ball. The sensing coil forms a portion of an audio frequency resonant circuit that performs the detecting function. This circuitis shown in Fig. 24 and will be fully described here- 'inafter. For the present it is suflicient to note that each,

of these detector circuits contains a relay, the contacts of which are arranged in a relay tree circuit, as shown. in Fig. 25.. The sensing coils, relays, and associated contacts constitute a verifier which checks the accuracy of the selected code groups.

If the verifier indicates that an incorrect code group has been selected, then the cylinder 127 discards the. incorrect group. If the verifier indicates that the correct code group has been selected, then the cylinder 127 rotates counterclockwise, as viewed in Fig. 5, to convey the code group to the next stage of the apparatus.

The code groups that are found to be correct by the verifier are deposited in flow passage means in the form of tubes 132 which conduct them to a code transfer station 134. The transfer station includesa rotatable cylinder 135 formed with five axially spaced, semi-cylindrical grooves 136 and is shown in its normal position in Fig. 5 with its grooves directing the code groups from the tubes 132 into the tubes 138.

The tubes, 138 constitute the blind storage section of the apparatus and their capacity is theoretically unlimited,

but more important, from a practical standpoint a storage capacity in the hundreds or even thousands may be provided at little additional cost. The blind storage tubes 138 are preferably formed into one or more loops to provide maximum capacity within a minimum of space. Successive groups of balls may be selected, verified, and deposited in the blind storage tubes until the entire train being classified has been set up in the apparatus. Thus the present apparatus is capable of recording an entire train in one continuous operation so that the operator may first complete the recording operation and then devote his full and undivided attention to supervising the classification operation and making the necessary reroutings, as previously indicated.

Should the train or trains being classified exceed the storage capacity of the apparatus, provision is made for notifying the operator and automatically de-energizing the code selecting mechanism. For this purpose the pilot channel blind storage tube 138 is provided with a sensing coil 137. This coil actuates the circuits of Figs. 29 and 30, as will be explained hereinafter.

The blind storage tubes 138 also constitute flow passage'means that feed into a code station 139 within which is mounted a rotatable cylinder 140. The code station 139 is generally similar to the verifier code station 126 having a sensing coil 141 associated with each of the tubes 138 and having the cylinder 140 formed with five axially spaced pockets 142 which face downwardly when the cylinder is in normal position.

' As the first code group reaches the bottom end of the tubes of the blind storage section, the balls encounter an imperforate surface portion of the cylinder 140. The arrangement is such that when a code ball is supported by the cylinder 140, it will be in the field of one of the sensing coils 141.

i The code station 139 constitutes the top level of the visible storage section, and in the preferred form of the apparatus there are provided four such levels arranged in series relationship. The top level for convenience is termed the fourth level and it is connected to the third level by flow passage means in the form of tubes 144. The third level is identical with the fourth and comprises a code station 146 having a rotatable cylinder 147 provided with the usual pockets 148. Each of the tubes 144 is provided with a sensing coil 149. The third level is connected with the second level by the tubes 151 and the second level comprises an identical code station 153 having a rotatable cylinder 154 with the usual pockets 155. Each of the tubes 151 is provided with a sensing coil 156. Finally, the second level is connected to the 'first level by the tubes 158 and the first level comprises an identical code station 160 having a rotatable cylinder 161 with five axially spaced pockets 162. A sensing coil 163 is provided for each of the tubes 158.

The cascading of the code groups through the successive levels of the visible storage section is controlled by the pilot channel which always has a steel ball. When a code group arrives at the code station 139, the sensing coil 141 of the pilot channel detects the presence of a steel ball, and if there is no code group at the next lower level, a motor control circuit will become operative to energize a motor (not shown) and drive the cylinder 140 counterclockwise, as viewed in Fig. 5. The pockets 142 will sweep past the tubes 138, receive the first code group, deposit it in the tubes 144, and complete the cycle of rotation. The code group thus cascades down to the third level where the procedure will be repeated. This process continues until there is one code group at each level of the visible storage section.

The visible storage section controls an indicator panel that is mounted on the console of Fig. 7, as indicated generally at 165. The indicator panel consists of four horizontal rows of lights, there being eight lights in each row corresponding to the eight receiving tracks. Ihe lights of each row of the indicator panel are arranged 10 in relay tree circuits of the type shown in Fig. 3, and these circuits are controlled by the sensing coils at each level of the visible storage section, whereby the receiving track represented by the code group at each level of the visible storage section is displayed on the indicator panel.

The apparatus will remain in the set-up condition until the cars of the train, in approaching the hump 100, pass over an approach section of track, indicated at 101 in Fig. 2, and actuate an associated track detector circuit. This track circuit controls a relay, one of the contacts of which is in the motor control circuit for the cylinder 161 located in the first level of the visible storage section. When a car passes over the approach section 101, the cylinder 161 rotates clockwise, sweeping past the tubes 158 to receive the first code group and convey it to the tubes 166. Thus the first car, in passing the approach section for the main track switch SW1-8, causes the associated descriptive code group to cascade from the first level of the visible storage section to the control section of the apparatus.

The control section of the apparatus is, in a sense,

a mechanical analogue of the classification yard track layout. Corresponding to the track switches are the mechanical code stations, and corresponding to the branch sections of track are the flow passage means in the form of tubes that interconnect the mechanical code stations. The tubes 166 correspond to the entrance track and feed into a code station 168 that corresponds to main track switch SW1-8. The code station 168 includes a. rotatable cylinder 169 having the usual pockets 170 and adapted to rotate in either direction to convey the code groups either to the tubes 172 or to the tubes 173. The tubes 172 conduct the code groups to code station and the tubes 173 conduct the code groups to code station 180. Thus code stations 175 and form the second level of the control section and correspond to track switches SWS-S and SW1-4, respectively. Code station 175 includes a rotatable cylinder 176 having the usual pockets 177 and is adapted to rotate in either direction. Similarly, code station 180 includes a rotatable cylinder 181 having the usual pockets 182 and is adapted to rotate in either direction. The cylinder 176 conveys the code groups either to the tubes 185 or to a collecting hopper 214, and this corresponds to receiving track 5. The cylinder 181 conveys the code groups either to the tubes 186 or to the collecting hopper and this corresponds to receiving track 4. The tubes 185 and 186 feed the code groups into code stations 191 and 196, respectively, and these stations constitute the third level of the control section and correspond to track switches SW6-8 and SW1-3, respectively. The rotatable cylinder 192 having pockets 193 is adapted to convey the code groups either to the tubes 201 or to the collecting hopper and the rotatable cylinder 197 having pockets 198 is adapted to convey the code groups either to the tubes 202 or to the collecting hopper.

The tubes 201 and 202 feed the code groups into code stations 203 and 208, respectively. These stations constitute the fourth level of the control section and correspond to track switches SW7-8 and SW1 2, respectively. The rotatable cylinders 204 and 209 rotate in either direction to convey the code groups to the collecting hopper 214.

The arrangement of the control section is such that the code station 168 which corresponds to the first or A switch level is controlled by the code ball in channel A. Similarly, code stations 175 and 180 are controlled by the code ball in channel B; code stations 191 and 196 are controlled by the code ball in channel C; and code stations 203 and 208 are controlled by the code ball in channel D. Therefore, each code station of the control section is provided with only two sensing coils, one for the pilot channel and one for the operative code channel. 

